Concrete is a widely used material due to its versatility, but it does have its drawbacks, mainly its brittleness. This issue has led materials scientists to search for ways to create concrete that can heal itself. A new method developed by a team led by mechanical engineer Congrui Grace Jin of Texas A&M University involves using synthetic lichen to achieve this self-healing property.
Traditional methods of creating self-healing concrete have involved using bacteria, but these approaches have required external sources of nutrients to sustain the healing process. The new approach using synthetic lichen is fully self-sustainable, eliminating the need for human intervention in supplying nutrients.
Lichens are unique organisms that consist of a symbiotic partnership between fungus and cyanobacteria or algae. The researchers designed a custom lichen that incorporates cyanobacteria to fix carbon dioxide and nitrogen from the atmosphere, along with a filamentous fungus that promotes the precipitation of calcium carbonate. This calcium carbonate acts as a binding agent, repairing cracks in the concrete and preventing further damage.
In laboratory tests, the synthetic lichen was able to effectively heal cracks in concrete by depositing calcium carbonate. This method mimics the ancient Roman technique of using chemical reactions to produce calcium carbonate for concrete repair. Unlike bacteria-based approaches, the synthetic lichen does not require external sources of nutrients and can operate autonomously.
The researchers plan to further investigate how the synthetic lichen performs with pre-existing cracks in concrete. The results of their study have been published in Materials Today Communications, showcasing the potential of this self-healing concrete technology.
In conclusion, the development of self-healing concrete using synthetic lichen presents a promising solution to the issue of concrete brittleness. This innovative approach could significantly improve the lifespan of concrete structures, offering a sustainable and efficient way to maintain infrastructure.
